MONTPELIER — The 11 members of the House Committee on Health Care will dedicate much of the 2013 legislative session to solving a fiscal dilemma that threatens to spike insurance costs for nearly 20,000 Vermonters.

Rep. Mike Fisher, a Lincoln Democrat and chairman of the health care committee, said he has grave concerns about the increased out-of-pocket expenses awaiting some lower-income residents beginning in January 2014. The potential jumps in premiums and deductibles will affect a portion of Vermonters now receiving subsidized coverage in two state-sponsored programs, called VHAP and Catamount Health.

“It’s an issue that’s of concern to a lot of members, and it’s going to be a big focus of ours,” Fisher said.

The cost increases are related to the health benefits exchange, a federally mandated online marketplace designed to improve access to insurance by lowering costs.

But the implementation of the exchange will also usher in the end of VHAP and Catamount. And since federal assistance in the exchange won’t be nearly as robust as what’s available in the state programs, more than 17,000 residents enrolled in VHAP or Catamount Health are expected to see potentially dramatic increases in their out-of-pocket health care costs.

“We need to look first at what is the impact and then at what are our options,” Fisher said.

Administration officials say it could cost as much as $18 million to hold harmless every Vermonter facing higher health care costs under the exchange. While Gov. Peter Shumlin says his budget proposal next month will deflect at least some of the impact on poor and working-class residents, he has said the state can’t afford to eliminate it entirely.

Fisher said his committee will begin wrestling in January with many of the same questions the Shumlin administration is grappling with now.

“We’ll have to look at whether there is the potential for doing an additional state subsidy,” Fisher said. “And if there is money to do it, where would it be best focused?”

Fisher said his committee also will continue its long-running work on payment reform, with a specific focus on “accountable care organizations.”

An ACO is a network of health care providers who agree to care for a certain number of patients over a set period of time for a fixed cost. If costs incurred by the patients are less than what was agreed upon, then the providers keep the difference. If costs exceed the threshold, then providers take a loss on the deal.

“It challenges providers to take some responsibility,” Fisher said. “In the past, the risk has always been on the insurer side. By having providers share some of that risk, you give them a positive stake in the cost containment we’re trying to achieve.”

Fisher said the ACO concept, created by the federal government, might require some legislative oversight.

“I really want it to work,” Fisher said. “And if we have multiple ACOs fighting over the same lives, that’s not productive. It needs to happen in a way that is predictable and works for providers and for patients.”

Downstairs in the Senate, Fisher’s counterparts on the Senate Committee on Health and Welfare will have their hands full with mental health.

In the wake of the closure of the Vermont State Hospital in 2011, lawmakers last year passed legislation overhauling the mental health system. But Sen. Claire Ayer, Democratic chairwoman of the Senate Committee on Health and Welfare, said the job is far from done.

“We made a lot of assumptions about where it’s best to get care and who should be delivering it, and we need to check in and make sure those assumptions were correct,” Ayer said.

She said the Legislature must also contend with revenue issues that might complicate the plan, notably the news that the hospital’s replacement won’t be eligible for 90 percent federal reimbursement.

Ayer said she also plans to devote committee time to the continued problems at Adult Protective Services, a state division whose alleged failure to protect its elderly clients resulted in a high-profile lawsuit. Shumlin last spring vetoed a bill that would have required the administration to provide a report on the program’s deficiencies. In the absence of that report, Ayer said, her committee will have to do its own legwork.

The Senate Committee on Health and Welfare may also host hearings on a controversial bill that would allow doctors to prescribe some terminally ill patients a lethal dose of medication. Ayer said she likes the idea of holding joint public hearings on the bill — which supporters call “death with dignity” — with the Senate Judiciary Committee.